Molding machine



Dec. 24, 1940. A. A. scoTT HOLDING MACHINE 5 Sheets-Sheet 1 www ou gms/mko@ Original Filed OCT.. 29, l1936 De 24, 1940 A. Asco-rr 2,226,326

Momma MACHINE Original Filed Oct'. A29,- 1956 .5 Sheetsrsheet 2 Dec. 24, 1940. A A. SCOTT HOLDING MAGI'UNE Original Filed Oct. 29, 19256` 5 Sheets-Sheet I5 A. A. sco-r1 IOLDJQNG. MACHINE Original- Fi1 ed Oct'. 29', 1956 5 Sheets-Sheet 4 o o ,o o

o I @5I I I I I I z I I I X I I I i oa i Patented Dec. 24, 1940 PATENT OFFICE MOLDING MACHINE Alexander A. Scott, Knoxville, Tenn., assigner to Wheeling Stamping Company, Wheeling, W. Va., incorporation of West Virginia Application october 29, 1936, serial No. 108,259

- Renewed July 8, 1940 This invention relates to an improvement in molding machines, and more particularly to such machines which are designed for molding bottle i caps or other molded products which are molded with screw-threads therein, and which threads '15 of an unscrewing unit into engagement with the molded products on one ofthe molds after separation of the molds and then, by rotating the products, they are disconnected from the molds simultaneously so that a multiplicity of the mold- '20 ed products may be readily removed Without the necessity for individually unscrewing these products manually, as has been necessary heretofore. Provision is made for' retaining the molded products in the unscrewing units for unitary 25 removal thereof from between the molds .to a

point where they may be discharged into a suitable container for further operation or packaging. This invention preferably contemplates` the' employment of unscrewing heads, in the unit, one for each moldedproduct, which heads have provision for detachable connection of the molded products therewith, and preferably the con'- nectlon is flexible, so as to avoid breakage or injury to the molded products and these unscrewing heads are designed so that theymay be rotated simultaneously as, for instancez by means of racks, meshing with teeth on the peripheries of the units, which racks rotate the heads for unscrewing the caps from'the molds. A preferred embodiment/of this invention is illustrated in the accompanying drawings, in

whichz.

Fig. 1 is a side elevation of a molding machine, 45 showing the invention applied' thereto;

Fig. 2 is an end elevation thereof; Y f Fig. 3 is an enlarged vertical sectional view through the upper mold, and a portion yoit the uriscrewing unit in position for unscrewing the 50 molded products;

Fig. 4 is a similar view showing the unscrewing unit lowered out of operative 'relation with the mold;

Fig. 5 is a top plan view of a portion of the un- 55 screwing unit;

l the unscrewlng unit;

Fig. 6 is a vertical sectionalview through a portion thereof. on the line 8 6 of Fig. 5;

Fig. 'I is a top plan View of the unscrewing unit, and a. portion of its operating mechanism;

Fig. 8 is a side elevation, partly in section of 5 Fig. 9 is a longitudinal sectional view therethrough, substantially on theline 8--9, of Fig'. '1;

and

Fig. 10 is a detached perspective viewl of the lo unscrewing head and its ring.

The invention is illustrated in connection with a. press for molding screw caps, such as are used on bottles, jars, or' the like, and which are ordinarily molded from a material which is initially plastic and granulated, and is run through a machine and pressed into small compact tablets of the desired size and weight; each tablet being designed to form one molded cap and is placed into one of the molds and pressed into the desired shape to -form the screw cap, or the like.

A hydraulic press, such as is commonly used for molding such screw caps, is illustrated in Figs. 1 and 2, to show the application of the invention thereto, and is designated generally by the numeral l. 'I 'his press is shown as having the usual upper steam plate 2, carrying a mold plate 3, from which depend mold screw plugs or plunger elements I, designed to i'orm the. threaded interior of the molded screw caps. The press is provided also with the usual head 5, designed for upwardand downward movement by hydraulic means of the usual form, which need not be illustrated in detail. The head 5 carries a steam plate 6, and `...mold 1, which latter has cavities in the upper surl caps and sets, so as to ypermit separation of they molds for removal of the capsfrom the screw plugs which form the upper molds. The molded screw capsare retained on the plugs by threaded connections therewith and must beunscrewed, in order to' be removed therefrom. This invention has provision for unscrewing the caps from the plugs, mechanically and as a unit.

The mechanism for unscrewing the caps mechanically is supported on a frame which is .55

mounted adjacent the press I, and in the form illustrated, this frame comprises upper and lower f' side angle bars 8 and 9, each of which has one end secured to and supported upon the frame of the press, while the opposite end is secured to upright end angle bars I0, which are suitably secured together to form a rigid end frame vi'or the main supporting frame of the unscrewing mechanism. Y

Extending between the press I, and the end frame bars 10, at opposite sides of the machine are track plates I I, which are designed for vertical movement, having their downward movement limited by means of stops I 2, at opposite sides 15 of the press I, and by slots I3 in the opposite ends 'of the plates II, receiving opposite ends of a rod I4, which extends transversely of the frame and is supported by the upright bars I0.

The track plates are supported by sets oi 2Q toggles I5, plvotally supported by the stationary side bars 9 of the frame, and the sets oil toggles on each side of the machine are joined together by a connecting bar I6, which is pivoted'thereto at the joints upon rods I1, which extend trans- 25 versely of the machine between lthe corresponding sets of toggles. Brackets I8 and I9 are carried by the connecting bars I6, andextend upwardlytherefrom, supporting at their upper ends side bars 20,

each of which has a depending bracket 2|, in position to be engaged for movement of the toggle mechanism as will be described hereafter.

The unscrewing unit is carried by the track plates II, as shown in Figs. 2 and 3. The unscrewing unit, in the form shown, is constructed 35i in the form of a carriage or trolley structure, having upper and lower plates 22 and 23, held in proper relation by spacers 24, as shown in Fig. 6. The upper plate 22 is slightly longer than the lower plate 23, and slides upon the track plates 40 I I to support the unscrewing unit thereon. Journaied within the plates 22 and 23 are a multiplicity of rotary heads 25, each of which is cylindrical and has an internal shoulder 26, upon which is seated a resilient cushion ring 21, preferably of soft rubber, in order to snugly receive and fit on the caps, as the unscrewing unit is moved into contact therewith, while the caps are on the mold plugs 4. The .heads 25 are supported 50- on a Vsub-plate 28, which underlies the plate 23, and all these platesare held together by bolts 29 extending through the spacers 24. Each of the heads 25 has an external gear 3l), the teeth of which mesh with rack bars 3|, which extend be- 55 tween the upper and lower plates 22 and 23, and

each of these rack bars 3| is held in proper mesh with arow of heads 25, by pins 32, which extend through the plates 22 and 23. It will be noted from Figs. 5 and 7., that the heads 25 are arranged o in regular order in rows, so that a rack bar'may be used to operate a row of rotary heads, in order to turn the same for'unscrewing the caps which are received by the rings 21 when the unscrewing unit is moved onto the caps held by the upper 65 molding plugs 4. Y

'I'he rack bars 3| are attached by brackets 33 to' the underside of a .plate 34, slidably mounted upon the bracket plates Il.' Mounted upon the I plate 34 is an angle bracket 35, to'which a hollow 70 plunger 36 is secured," the plunger also extending into a T`iltting 31. At one side, the T-itting 31, has a pipe 38, extendingl thereto from a water tank supported at a higher point for now of water under gravity to the fitting, a check-valve 39 be- 75 ing provided'm the pipe as to prevent backward flow o1' water through the pipe. At the opposite side, the .fitting 31 has a water discharge pipe 40 connected therewith, the pipe 40 having a valve 4I therein controlled by a spring-pressed valve stem 42, which is arranged in position for operation by a screw abutment 43, carried by a bracket 44, on the plate 22 of the unscrewing unit, the screw-threaded connection of the abutment 43 permitting adjustment thereof, for properly timed operation of the valve 4|.

The hollow plunger 36 extends through al packing gland 45, in a cross-head 46, which cross-head 46 has a hollow piston rod 41, secured thereto, as shown in Figs. 7 and 9, the piston rodr 41 being attached to a piston 48 mounted in a cylinder 49, supported by the framework of the machine and having a iluid inlet 50, at its extreme outer end for admitting 'a suitable fluid, such as water into the outer end of the cylinder under pressure sufflcient to move the piston 48.

The cross-head 46 is supported by an angle bracket 5|, slidably mounted upon the plate 34 for movement relative tosaid plate. Extending laterally in opposite direction from the cross-head Y 46 are operating arms 52, the ends of which are angular in shape for operation of the toggle mechanism thereby, as will be described hereafter. After the molding of the caps, as described above, the hydraulic press is opened and the molded caps are ready for removal from the screw plugs in the top mold. Water or other fluid is then admitted into the outer end of the hydraulic cylinder 49, under sufficient pressure to move the piston 48 and piston rod 41 forward, to the left in the drawings. In the tmeantime., water has been admitted through the pipe 38,' T-tting 31, and hollow plunger 36, into the hollow piston rod 41, substantially to ll the space therein between the piston and the plunger 36, so that upon -movement of the piston 48 forward in the hydraulic cylinder 49, this motion is transmitted through the plunger 36, to nieve not only the cross-head 46, but also the plate'y34 forward. This movement of the plate 34 transmits the motion through the rack bars 3|, to the unscrewing unit, sliding the latter forward on the track plates I I to a. position between the upper and lower molds of the hydraulic press until the movement of the plates 22 and 23'is stopped, being regulated so as to position the unscrewing heads directly under the corresponding screw plugs and the caps thereon.

When movement of the' plates 22 and 23 of the unscrewing unit is stopped, the cross-head 46 and rack, bars 3|, may continue to move so that the rack bars 3| are moved on through the unscrewing plates, during which time they revolve the empty heads 25, until the rack bars have extended or projected almost their entire lengths in their travelthrough the unscrewing plates. The piston rod 41 and cross-head 46 continue to `move forward a sulcient distance for engagement of the arms 52 with the brackets 2| (Fig. 1), in order to straightenthe toggle mechanism to raise the unscrewing unit into` engagement with the caps carried by the upper mold. At this time, the valve stem, 42 moves into engagement with the adjustable screw stop 43, to release the water from within the hollow plunger 36, and hollow piston rod 41, through the pipe 45 which-thereby permits further movement of the cross-head 46 and arms 52 relative to the plate 34, without movement of the rack bars 3|, which extended movement is for the purpose oi! raising the unscrewing unit into engagement with the caps. If the rack bars were operated torotate the heads 25, during this movement, it would cause the caps to beI screwed further on to the screw plugs with a tightening action which would break .the caps or damage the rubber rings by friction, so that it is necessary that the heads 25 remain stationary during this connecting motion.

As the arms 52 engage' the brackets 2| of the side bars 20, and move the brackets forward. such motion is transmitted to the connecting bars I6 of the togglesl I 5, straightening the latter and thereby raising the track bars II, and the unscrewing unit carried thereon, pressing the rubber rings 21 over the screw caps carried on the lthreaded plugs 4 of the upper mold.

The unscrewing unit is now in proper position for unscrewing the caps from the screw'plugs of the upper mold,which must be done by reversing the travel of the rackA bars 3i. The

.cross-head 45 andthe arms 52 havingmoved forward in order to operate the togglesto engage the unscrewing unit with the caps, have been moved by the full forward extension of the piston rod 41, in the hydraulic cylinder 49. A latch Vplate 53 is vcarried-by each arm 52, and when the latter is moved forward, the latch plate 53 drops behind a stop 54 (Fig. '7) on the plate 34.

When the rack bars 3| have been retracted about three-fourths of their lengths, the caps have been unscrewed, and then the rack bars stop momentarily while'the unscrewing unit with the caps in the rubber rings 21 is lowered by the toggles when the arms 52 move back relative to the tracks 2i. The retracting movement is caused by admitting water or other uid through the Apipe 49a into the inner end of the cylinder' dii and force the piston back in the cylinder.

The cross-head 48 continues to move, and a cam groove 55 in each latch plate 53 engages a pin 55, secured to bracket I8, and raises the latch plate 53, allowing the cross-head 48, to continue to move until the unscrewing unit and racks stop. The arms 52 contact bars 51, attached to the inner sides of brackets I 8, posltivelymove the side bars 20, and connecting bars I6 to lower the toggles and bracket plates I I with the unscrewing unit thereon. ment continues until the unscrewing unit has been moved out of the hydraulic press, where it Ais disposed directly beneath a knock-out plate 58, having plugs 59 thereon, for pressing the screw caps out of the rubber rings 21. 'I'his knock-out plate 58 may be raised and lowered by any suitable means, such as a hydraulic hoist so as to simultaneously remove the screw caps from the unscrewing unit and enabling them to be directed to a suitable container beneath the frame work of the machine.

Attached to rod I1, of one of the toggles I5, is a hydraulic cushion $0, having a piston therein and to the outer end of the cylinder of the piston is a water pipe 6I, with a check-valve 62, therein. When the toggle I is straightened, the piston is drawn forward in the slide which draws water into the outer end of the cylinder through the check-valve, but upon closing of the checkvalve the water is trapped in the outer end of the slide and is discharged only through a relatively small opening 63, in the check-valve which allows aslow discharge from the cylinder which allows only a slow downward movement of the bracket plate and the unscrewing unit carried` thereby.

The retractlng move- 1. A method of removing screw-threaded molded products from a plurality of molds mounted in a press and each comprising superimposed separable parts, with one of which mold parts its respective product has screw-threaded connection, comprising moving a unit comprising a plurality of rotatable unscrewing devices between said mold parts after they have been separated and while in the press into engagement with the products, and unscrewing a plurality of said products from their respective mold parts lby rotary movement of said devices between said separated mold parts.

.2. In' a method of molding products between molds separable to provide a space therebetween,

with one of which theprOducts are retained after molding, the step of removing said prod-- ucts comprising moving a unit comprising a plurality of unscrewing heads between -separated molds, moving said heads into engagement with the products, rotating the heads to remove the products from one of the molds, retaining the products in the heads and simultaneously revhaving meansfor engaging a molded product screw-threaded on a mold, and having a gear thereon, rack bars slidably mounted in the unit and meshing with the gears of the plurality of rotary heads to rotate the same and unscrew the products from the molds.

5. In a machine of the character described,

the combination of a unit having a plurality of rotary heads mounted therein, each of said heads having means for engaging a molded product screw-threaded on a mold, and having a gear thereon, rack bars slidably mounted in the unit and meshing with the gears of a plurality of rotary heads to rotate the same and unscrew the products from the molds, and means for simultaneously moving a plurality of vsaid rack bars longitudinally relative to the unit.

6.'In a machine of the character described, the combination of a unit having a plurality of rotary heads mounted therein, each of said heads having means for engaging a molded product screw-threaded on a mold, and having a gear thereon, rack bars slidably mounted in the unit and meshing with the gears of a' plurality of rotary heads to rotate the same and unscrew the products from the molds, vand plunger operated means operatively connected with the rack bars for moving the same longitudinally relative to the unit.

7. In a machine of the character described, the combination of an approximately cylindrical unscrewing head for removing a molded product from a mold part with which it hasl screwx.

while holding the product therein, means fortached to the mold, and means for holding the head against bodily endwise movement during unscrewing ot the product.

5; 8. In a molding machine of the character described, the combination of separable molds for molding l products therebetween with screwthreaded connections between said products and a mold, means for unscrewing the products from the molds, andmeans for moving the unscrewinl means yinto the space between said molds after separation for engaging the products to remove the same.

9. In a press of the character described, the combination oi! separable molding heads for molding products therebetween, guides for one of said heads for movement thereof relative to the other head, one of said heads having means for screwthreaded connection between the molded products jl and said head, means for unscrewing the 'I products from the head, and means for moving the unscrewing means into the space between said molding` heads intermediate the guides after separation of the heads for engaging the products to remove the same.

10. In a molding machine of the character described, the combination of separable molds for molding products therebetween of the characterwherein the molded products have a screw- -v threaded engagement with one of the molds,

means` for unscrewing the products from the molds, and means for moving the unscrewing means into the space between said molds after separation for engaging the products to remove 85f the same.

11. In a press of the character described, the

combination of separable molding heads for molding products therebetween, guides for one of said heads for movement thereof relative to the other 'head, one of said heads having means for screwthreaded connection between the molded products and said head, means for unscrewing the products from the head, and means for moving the unscrewing means into the space between said mold- 45. ing heads intermediate the guides after separation of the heads for' engaging the products to remove the same and for movement out of the space intermediate the guides to a point wholly externally of the press.

12. In a press of the character described, the combination of separable mold parts for molding products therebetween, one of said mold parts having pins constructed to mold products therearound with screw-threaded connections therewith, a support carrying a 'plurality of rotary heads having means for engaging said molded products to unscrew the same from the pins, means for moving said support and heads into the space between said mold parts after separa- 50 tion for engaging the products, and means for -rotating the heads relative to the pins to unscrew the products therefrom,

13. In a molding machine ofthe character .described. the combination of separate upper and c5 lower molds for molding products therebetween, an unscrewing unit having means for engaging and removing the products from one ofthe molds, means for moving said unit between' the molds 'when said molds are separated and into contact 70 with the products on one of the molds, and means for operating said unit to remove the products from the mold for removal with the unit.

y 2,220,326 turning said head to uns-crew the product vat-l 14. In a machine oi' the character described, the combination of mold parts constructed for molding products with screw-threaded connections between the products and one of the mold parts, oi a'plurality of rotary heads having means 5 for engaging the molded products on the moldv part, and means geared with a plurality of said heads for rotating the same.

15. In a machine of the character described, the combination of mold parts constructed for l0 molding products with screw-threaded connections between the products and oneA of the mold parts, a unit having a plurality o! rotary h eads' journaled therein, said heads having means for engaging the molded products on the mold part, 15 and rack means geared with a plurality of said heads for rotating the same simultaneously.

16. In a machine of the character described, the combination of mold parts constructed for molding products with screw-threaded connec- 20 tions between the products and one of the mold parts, a unit having a plurality of rotary heads journaled therein, said heads having means for engaging the molded products on the moldpart, rack means geared with a plurality of said heads 25 for rotating the same simultaneously, and means for holding the heads against bodily endwise movement in the unit during rotation thereof.

A 17. Apparatus for molding articlesmcomprising a` press having mold means thereon shaped to 30 form a plurality of articles having screw-threaded engagement with said mold mea/ns, a stripping means mounted on thepress having a driven member thereonA for Irictionally engaging the formed articles to unscrew them' from the mold 35 means, one of said means being movable with respect to the other to present the mold means to the stripping means, and means -for moving said Imovable means on said press.

18. Article-molding apparatus comprising a 40 press having upper andlower mold members movable vertically relatively to each other, one of said mold members having a number of plunger elements projecting thereof, a supporting means on the press, a carriage on the supporting means 45 movable in a horizontal plane along the supporting means between the said upper and lower mold members, whereby it may be positioned adjacent the several plunger elements, means independent of the movementot the mold members o for raising and lowering the carriage, and stripping means on the carriage which is moved by the raising and lowering movement of the carriage into and out .of 'cooperating position with 55 the plunger elements adjacent to which the carriage is positioned. s 19. The combination with a press for forming plastic articles having a multiple mold with mold units arranged inparallel rows thereon and havw ing a second mold for cooperation with the rst and of a character wherein thev articles when formed are vin screw-threaded engagement with f one of the molds, of a supporting frame mounted on the press, a trolley structure mounted on the supporting frame and movabletherealong, said supporting frame and't'rolley being so arranged kthat the trolley may move 4back and forth beillmtxANDnitv s. sco'rr. 

